Scott,
I worked on a proposal for a new 911 system in New York City. I doubt SBC (or local LEC) will want to sent ss7 calls to a call manager server. Having said that they can provision regular ISDN trunks that have ANI information on the inbound 911 call. So call manager can definitely answer the calls.
I guess you already possess the ALI dip software.
I wish you success working with the LEC.
Bob